The interdisciplinary study of the brain activity linked with cognition (including perception, thinking, memory, and language).

Dual Processing

The principle that information is often simultaneously processed on sperate conscious and unconscious tracks.

Selective Attention

The focusing of conscious awareness on a particular stimulus.

Inattentional Blindness

Failing to see visible objects when our attention is directed elsewhere.

Change Blindness

Failing to notice changes in the environment.

REM Sleep

Rapid eyes movement sleep, a recurring sleep stage during which vivid dreams commonly occur. Also known as paradoxical sleep, because the muscles are relaxed (except for minor twitches) but other body systems are active.

Alpha Waves

The relatively slow brain waves of a relaxed, awake state.

Sleep

Periodic, natural, reversible loss of consciousness - as distinct from unconsciousness resulting from a coma, general anesthesia, or hibernation.

Hallucinations

False sensory experiences, such as seeing something in the absence of an external visual stimulus.

Delta Waves

The large, slow brain waves associated with deep sleep.

Insomnia

Recurring problems in falling or staying asleep.

Narcolepsy

A sleep disorder characterized by uncontrollable sleep attacks. The sufferer may lapse directly into REM sleep, often at inopportune times.

Sleep Apnea

A sleep disorder characterized by temporary cessations of breathing during sleep and repeated momentary awakenings.

Night Terrors

A sleep disorder characterized by high arousal and an appearance of being terrified; unlike nightmares, night terrors occur during stage 4 sleep, within two or three hours of falling asleep, and are seldom remembered.

Dream

A sequence of images, emotions, and thoughts passing through a sleeping person's mind. Dreams are notable for their hallucinatory imagery, discontinuities, and incongruities, and for the dreamer's delusional acceptance of the content and later difficulties remembering it.

Manifest Content

According to Freud, the remembered story line of a dream (as distinct from its latent, or hidden, content).

Latent Content

According to Freud, the underlying meaning of a dream (as distinct from its manifest content).

REM Rebound

The tendency for REM sleep to increase following REM sleep deprivation (created by repeated awakenings during REM sleep).

Hypnosis

A social interaction in which one person (the hypnotist) suggests to another (the subject) that certain perceptions, feelings, thoughts, and behaviors will spontaneously occur.

Posthypnotic Suggestion

A suggestion, made during a hypnosis session, to be carried out after the subject is no longer hypnotized; used by some clinicians to help control undesired symptoms and behaviors.

Dissociation

A split in consciousness, which allows some thoughts and behaviors to occur simultaneously with others.

Psychoactive Drug

A chemical substance that alters perceptions and moods.

Tolerance

The diminishing effect with regular use of the same dose of a drug, requiring the user to take larger and larger doses before experiencing the drug's effect.

Withdrawal

The discomfort and stress that follow discontinuing the use of an addictive drug.

Physical Dependence

A physiological need for a drug, marked by unpleasant withdrawal symptoms when the drug is discontinued.

Psychological Dependence

A psychological need to use a drug, such as to relieve negative emotions.

A synthetic stimulant and mild hallucinogen. Produces euphoria and social intimacy, but with short-term health risks and longer-term harm to serotonin-producing neurons and to mood and cognition.

Hallucinogens

Psychedelic ("mind-manifesting") drugs, such as LSD, that distort perceptions and evoke sensory images in the absence of sensory input.

LSD

A powerful hallucinogenic drug; also known as acid

THC

The major active ingredient in marijuana; triggers a variety of effect, including mild hallucinations.

Zygote

The fertilized egg; it enters a 2-week period of rapid cell division and develops into an embryo.

Embryo

The developing human organism from about 2 weeks after fertilization through the second month.

Fetus

The developing human organism from 9 weeks after conception to birth.

Teratogens

Agents, such as chemicals and viruses, that can reach the embryo or fetus during prenatal development and cause harm.

Fetal Alcohol Syndroms (FAS)

Physical and cognitive abnormalities in children caused by a pregnant woman's heavy drinking. In severe case, symptoms include noticeable facial misproportions.

Habituation

Decreasing responsiveness with repated stimulation. As infants gain familiarity with repated exposure to a visual stimulus, their interest wanes and they look away sooner.

Cognition

All the mental activities associated with thinking, knowing, remembering, and communication.

Schema

A concept or framework that organizes and interprets information.

Assimilation

Interpreting our new experience in terms of our existing schemas.

Accommodation

Adapting our current understandings (schemas) to incorporate new information.

Sensorimotor Stage

In Piaget's theory, the stage (from birth to about 2 years of age)during which infants know the world mostly in terms of their sensory impressions and motor activities.

Object Permanence

The awareness that things continue to exist even when not perceived.

Preoperational Stage

In Piaget's Theory, the sage (from 2 to about 6 or 7 years of age) during which a child learns to use language but does not yet comprehend the mental operations of concrete logic.

Conservation

The principle (which Piaget believed to be a part of concrete operational reasoning) that properties such as mass, volume, and number remain the same despite changes in the forms of objects.

Egocentrism

In Piaget's theory, the preoperational child's difficulty taking another's point of view.

Theory of mind

People's ideas about their own and others' mental states - about their feelings, perceptions, and thoughts, and the behaviors these might predict.

Concrete Operational Stage

In Piaget's theory, the stage of cognitive development (from about 6 or 7 to 11 years of age) during which children gain the mental operations that enable them to think logically about concrete events.

Formal Operational Stage

In Piaget's theory, the stage of cognitive development (normally beginning about age 12) during which people begin to think logically about abstract concepts.

Stranger Anxiety

The fear of strangers that infant commonly display, beginning by about 8 months of age.

Attachment

An emotional tie with another person;shown in young children by their seeking closeness to the caregiver and showing distress on separation.

Critical Period

An optimal period shortly after birth when an organism's exposure to certain stimuli or experiences produces proper development.

Imprinting

The process by which certain animals form attachments during a critical period very early in life.

Basic Trust

According to Erik Erikson, a sense that the world is predictable and trustworthy; said to be formed during infancy by appropriate experiences with responsive caregivers.

Self-Concept

Our understanding and evaluation of who we are.

Adolescence

The transition period from childhood to adulthood, extending from puberty to independence.

Puberty

The period of sexual maturation, during which a person becomes capable of reproducing.

Primary Sex Characteristics

The body structures (ovaries, testes, and external genitalia) that make sexual reproduction possible.

Our ability to reason speedily and abstractly; tends to decrease during late adulthood.

Social Clock

The culturally preferred timing of social events such as marriage, parenthood, and retirement.

Associative Learning

Learning that certain events occur together. The events may be two stimuli (as in classical conditioning) or a response and its consequence (as in operant conditioning).

Classical Conditioning

A type of learning in which one learns to link two or more stimuli and anticipate events.

Learning

A relatively permanent change in an organism's behavior due to experience.

Behaviorism

The view that psychology (1) should be an objective science that (2) studies behavior without reference to mental processes. Most research psychologists today agree with (1) but not with (2).

Unconditioned Response (UR)

In classical, conditioning, the unlearned, naturally occurring response to the unconditioned stimulus (US), such as salivation when food is in the mouth.

Unconditioned Stimulus (US)

In classical conditioning, a stimulus that unconditionally - naturally and automatically - triggers a response.

Conditioned Response (CR)

In classical conditioning, the learned response to a previously neutral (but now conditioned) stimulus (CS).

Conditioned Stimulus (CS)

In classical conditioning, an originally irrelevant stimulus that, after association with an unconditioned stimulus (US), comes to trigger a conditioned response.

Acquisition

In classical conditioning, the initial stage, when one links a neutral stimulus and an unconditioned stimulus so that the neutral stimulus begins triggering the conditioned response. In operant conditioning, the strengthening of a reinforced response.

High-Order Conditioning

A procedure in which the conditioned stimulus in one conditioning experience is paired with a new neutral stimulus, creating a second (often weaker) conditioned stimulus. For example, an animal that has learned that a tone predicts food might then learn that a light predicts the tone and begin responding to the light alone.

Extinction

The diminishing of a conditioned response; occurs in classical conditioning when an unconditioned stimulus (US) does not follow a conditioned stimulus (CS); occurs in operant conditioning when a response is no longer reinforced.

Spontaneous Recovery

The reappearance, after a pause, of an extinguished conditioned response.

Generalization

The tendency, once a response has been conditioned, for stimuli similar to the conditioned stimulus to elicit simliar responses.

Discrimination

In classical conditioning, the learned ability to distinguish between a conditioned stimulus and stimuli that do not signal an unconditioned stimulus.

Respondent

Behavior that occurs as an automatic response to some stimulus.

Operant Conditioning

A type of learning in which behavior is strengthened if followed by a reinforcer or diminished if followed by a punisher.

Operant behavior

Behavior that operates on the environment, producing consequences.

Law of Effect

Thorndike's principle that behaviors followed by favorable consequences become more likely, and that behaviors followed by unfavorable consequences become less likely.

Operant Chamber

In operant conditioning research, a chamber (also known as a Skinner box) containing a bar or key that an animal can manipulate to obtain a food or water reinforcer; attached devices record the animal's rate of bar pressing or key pecking.

Shaping

An operant conditioning procedure in which reinforcers guid behavior toward closer and closer approximations of the desired behavior.

Reinforcer

In operant conditioning, any event that strengthens the behavior it follows.

Positive Reinforcement

Increasing behaviors by presenting positive stimuli, such as food. A positive reinforcer is any stimulus that, when presented after a response, strengthens the response.

Negative Reinforcement

Increasing behavior by stopping or reducing negative stimuli, such as shock. A negative reinforcer is any stimulus that, when removed after a response, strengthens the response.

Primary Reinforcer

As innately reinforcing stimulus, such as one that satisfies a biological need.

Conditioned Reinforcer

A stimulus that gains its reinforcing power through its association with a primary reinforcer.

Continuous Reinforcement

Reinforcing the desired response every time it occurs.

Partial (Intermittent) Reinforcement

Reinforcing a response only part of the time; results in slower acquisition of a response but much greater resistance to extinction than does continuous reinforcement.

Fixed-Ratio Schedule

In operant conditioning, a reinforcement schedule that reinforces a response after an unpredictable number of responses.

Fixed-Interval Schedule

In operant conditioning, a reinforcement schedule that reinforces a response only after a specified time has elapsed.

Variable-Interval Schedule

In operant conditioning, a reinforcement schedule that reinforces a response at unpredictable time intervals.

Punishment

An event that decreases the behavior that it follows.

Cognitive Map

A mental representation of the layout of one's environment. For example, after exploring a maze, rats acts as if they have learned a cognitive map of it.

Latent Learning

Learning that occurs but is not apparent until there is an incentive to demonstrate it.

Intrinsic Motivation

A desire to perform a behavior effectively for its own sake.

Extrinsic Motivation

A desire to perform a behavior to receive promise rewards or avoid threatened punishment.

Observational Learning

Learning by observing others.

Modelling

The process of observing and imitating a specific behavior.

Mirror and Neurons

Frontal lobe neurons that fire when performing certain actions or when observing another doing so. The brain's mirroring of another's action may enable imitation and empathy.